Electric motor and series of electric motors

ABSTRACT

An electric motor and modular system of electric motors includes at least a stator, rotor, and a housing, the modular system including several variants of electric motors, e.g., within one size, the housing having a mechanical interface that is arranged for connection to a bearing support, the bearing support including at least a bearing seat for the B-side bearing of the rotor shaft, at least two different bearing supports being alternatively connectable to the housing, a first bearing support including an additional interface for connection to a bottom part of a terminal box, or alternatively to a bottom part for power electronics, and the first bearing support forming a housing for a brake and/or a fan, a second bearing support being constructed in one piece with a bottom part of a terminal box.

FIELD OF THE INVENTION

The present invention relates to an electric motor and a series ofelectric motor(s).

BACKGROUND INFORMATION

German Published Patent Application No. 197 04 226 describes an electricmotor, where an adapter and a cover are put onto the housing of thestator, an electronic circuit having the functionality of a converterbeing provided in the interior chamber. In this context, it isdisadvantageous that the converter is thermally insulated in thedirection of the motor. Consequently, a high-power cooling body must beconnected to the converter. This cooling body is provided on theconverter in the direction of the motor and disadvantageously requires alarge unit volume. It is also difficult and expensive to manufacture. Inparticular, a design having cooling fingers is associated with highexpenditure.

The terminal box, i.e., connection box, of the electric motor is notaxially mounted, but laterally. However, in the case of some systems,there is little space available on the side of the motor.

SUMMARY

Example embodiments of the present invention may provide an electricmotor and a series of electric motors that includes different variants.In this context, however, the storage volumes and the costs may becomereducible.

According to an example embodiment of the present invention, an electricmotor includes at least a stator, a rotor, and a housing, the housinghaving at least one first mechanical interface that is provided forconnection to a bearing support, the bearing support including at leasta bearing seat for the B-side bearing of the rotor shaft, the bearingsupport including a further interface for connection to a bottom part,the bearing support forming a housing, e.g., for a brake and/or a fan,the bottom part having an interface for connection to a cover, thebottom part forming a housing for at least power electronics, whose heatmay be discharged directly, or at least indirectly, to the bottom part,the bottom part being connected to the bearing support in a thermallyconductive manner, so that the heat of the power electronics may bedischarged by the bearing support to the surrounding air.

In this context, it may be provided that no special cooling body isnecessary, but that the B-side bearing support of the electric motor maybe used for dissipating heat. Consequently, the entire electric motormay be designed to be more compact, and, e.g., the lateral space issmall.

In this context, power electronics should be understood to be at leastthe part of the electronic components that may control, e.g., switch,the motor currents. For a deliverable motor output of greater than 500W, a power-electronics heat loss of greater than 20 W, e.g., up to 300W, normally occurs, which is to be ultimately discharged to theenvironment. The heat loss to be dissipated increases by a value between20 and 80 Watt per kW of motor output.

In a modular system, the electric motors include at least a stator,rotor, and a housing, the modular system including several variants ofelectric motors, e.g., within one size, the housing having a mechanicalinterface that is designed for connection to a bearing support, thebearing support including at least a bearing seat for the B-side bearingof the rotor shaft, at least two different bearing supports beingalternatively connectible to the housing, a first bearing supportincluding an additional interface for connection to a bottom part of aterminal box, or alternatively to a bottom part for power electronics,and the first bearing support forming a housing for a brake and/or afan, a second bearing support being constructed in one piece with abottom part of a terminal box.

It may be provided that many different variants may be produced using asfew components as possible. A variant, which is as compact as possible,is obtainable for each functional requirement, using as few componentsas possible. The modular system, i.e., the series, may only providebearing supports having different interfaces. The housing of the statorremains unchanged. Therefore, it is usable in all of the variants of theseries. The interfaces of the bearing support to the housing of thestator allows different bearing supports to be attached. In the case ofone of these bearing supports, a terminal box may be integrated. In thecase of another, it is detachably connectible and may be alternativelyreplaced with a converter. The last-named interface to the terminal boxmay even be oriented to be offset 90° from the interface to the stator.Therefore, it does not have to be coaxially mounted.

The B-side bearing support, and not the housing of the stator, may beused for variation within the series. It not only allows the stator androtor plates to be constructed in a substantially identical manner, butalso allows, depending on the requirement, different unit volumes of thebearing support to be obtained, together with the terminal box or theconverter housing, in the B-side region. However, in the majority of themachines and systems in which electric motors are installed, more volumeis available in the B-side region than in the A-side region or in theregion over the front axial, i.e., A-side, region of the stator housing.In addition, for maintenance work, easier access is possible in theB-side region than in the A-side region.

The connections may be constructed to be impervious and detachable,using seals. Therefore, a high degree of protection is achievable, e.g.,at least IMP.

The interfaces of the bearing support are provided for mechanicalconnection to the above-mentioned parts. In addition, the bearingsupport also has other functions, e.g., the function of discharging heatof the power electronics from the interior chamber of the terminal boxor converter. In each case, the bearing support may always carry out thefunction of forming a housing for a fan rotating with the rotor shaft.This supplies cool surrounding air and consequently increases the heatflowing from the bearing support to the environment.

A further integrated function of the bearing support is to act as theguide device for the armature disk and friction disk of the optionallypresent brake in the axial direction. Therefore, the bearing supportunites the mechanical functions of the retention force for the B-sidebearing and the mechanical guide forces for the components of the brake,such as the armature disk, etc.

A housing cover may be connected to the bottom part, and a bottom partof a terminal box or bearing support may be connected to a one-piecelower part of a terminal box. In this context, it may be provided thatan interior region sealed off to have a high degree of protection may beprovided for sensitive electronics.

The lower part or lower part of a terminal box may be connected to thebearing support in at least two different orientations, e.g., inorientation directions offset 90° from one another. It may be providedthat the optimum orientation may be selected as a function of therequirement of the application, i.e., the type of construction of themachine or system.

Soft-start electronics may be provided instead of the converterelectronics. It may be provided that costs are reducible, since thedevelopmental expenditure of soft-start electronics is less, and theymay also be manufactured using fewer components.

At least the first bearing support may have a precision-machined contactsurface for connecting it to the power electronics in a thermallyconductive manner. In this context, it may be provided that the bearingsupport may be used as a mechanical mount and heat-dissipating device.

The power electronics may be connected to the bearing support in athermally conductive manner for discharging heat to the environment. Itmay be provided that the heat is discharged to a part that may be cooledby a stream of cooling air.

The second bearing support may be arranged to have a sensor, whichdetects, at the circumference of the fan, physical characteristics ofthe fan or of a component connected to it. It may be provided that thefan has a larger diameter than the rotor shaft, and that the angularresolution may be consequently improved. In addition, no expensive,complicated sensor system is necessary, but rather a magnetic ring or amagnetic foil is sufficient.

The first bearing support may form a housing for an electromagneticallyoperable brake and/or a fan. It may be provided that the bearing supportis cooled. In addition, an additional housing for the brake is notnecessary.

The first and second bearing supports may each be connectible to thesame kind of fan-hood grating. An advantage of this is that the samefan-hood grating may be used repeatedly within the series.

The housing of the stator may be connectible to a bearing support on theA-side, the bearing support including a bearing seat for accommodatingthe A-side bearing of the rotor shaft. It may be provided that theentire electric motor has three main housing parts, namely the housingof the stator and the two bearing supports. If an electric motor havinga larger torque is necessary, only the rotor shaft, together with therotor, the stator, and the housing of the stator, is to be exchangedfor, e.g., parts that are axially longer, the remaining parts being ableto be retained.

The bearing support may have guide devices for axially guiding thearmature disk of the brake. In particular, the guide devices arearranged as cut-outs. It may be provided that no special part isnecessary for carrying out the guide function, but that this functionmay be integrated into the bearing support.

Further aspects and features of example embodiments of the presentinvention are described in more detail below with reference to theappended Figures.

LIST OF REFERENCE CHARACTERS

-   1 bearing support-   2 armature disk-   3 magnet body-   4 bottom part of terminal box, bottom part of connection box-   5 coating support-   6 stator winding-   7 rotor shaft-   8 A-side bearing-   9 rotor-   10 B-side bearing-   11 friction disk-   12 fan blade-   13 fan-   14 housing cover-   15 housing-   16 seal-   17 seal-   18 screw-type conduit fittings as cable outlets-   19 fan-hood grating-   20 screw-type conduit fitting-   21 printed circuit board-   22 connection terminals-   23 printed circuit board-   24 electrical connector including plug and mating connector-   25 housing cover-   26 bottom part-   27 power electronics-   30 bearing support-   31 housing cover-   32 fan-hood grating-   33 labyrinth seal-   34 shaft sealing ring-   35 screw-type conduit fittings-   40 sensor-   41 magnetic foil that is applied to the fan-   51 depressions for labyrinth seal-   52 knockout-   53 cut-outs-   61 seal-   62 knockout-   63 bearing support-   64 terminal box-   91 bottom part

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a and 1 b are a plan view and sectional view of an electricmotor of an example embodiment of the present invention, having a brakeand a fan.

FIGS. 2 a and 2 b are a plan view and sectional view of an electricmotor of an example embodiment of the present invention, having a brakeand fan, where a bottom part replacing the terminal box is provided, thebottom part, together with the attachable cover, surrounding electronicsthat function as a converter.

FIGS. 3 a and 3 b are a plan view and sectional view of an electricmotor of an example embodiment of the present invention, having a brakeand a fan, the terminal box being formed in one piece with the B-sidebearing support.

FIGS. 4 a and 4 b are a plan view and sectional view of an electricmotor of an example embodiment of the present invention, having a brakeand a fan, the terminal box being formed in one piece with the B-sidebearing support, and the fan supporting a sensor ring that is detectableby a sensor.

FIGS. 5 a and 5 b are a plan view and sectional view of a bearingsupport according to an example embodiment of the present invention.

The bearing support, along with a connected terminal box, is illustratedin FIGS. 6 a and 6 b.

A corresponding electric motor is illustrated in FIGS. 7 a and 7 b.

A sensor is additionally illustrated in FIGS. 8 a and 8 b.

An electric motor having a fan, but not a brake, is illustrated in FIGS.9 a and 9 b.

FIGS. 10 a and 10 b are spatial, oblique front and back views of thebearing support and connected terminal box illustrated in FIGS. 6 a and6 b.

FIGS. 11 a and 11 b are spatial, oblique front and back views of thebearing support illustrated in FIGS. 5 a and 5 b.

DETAILED DESCRIPTION

Illustrated in FIGS. 1 a and 1 b is the bearing support 1 of an electricmotor having a brake. The bearing support has a bearing seat for B-sidebearing 10 of the electric motor. The bearing seat is suitably machinedfor this. The electric motor includes a stator winding 6, which isprovided inside housing 15, and a rotor shaft 7, which is supported onthe A side by bearing 8 in the A-side bearing support, and on the B sideby bearing 10 in the B-side bearing support. Rotor 9, including rotorshaft 7 and rotor plates, is arranged as a squirrel-cage rotor forforming an asynchronous motor. However, the rotor may also be arrangedto form a synchronous motor, reluctance motor, or another motor.

On its B-side end, the rotor shaft supports a fan 13 having fan blades12. Provided axially in front of this is a brake, which includes a brakecoil located in magnet body 3 and an axially movable armature disk 2.When current flows through the brake coil, armature disk 2 is pulledtowards it, counteracting spring force being overcome by spring elementssupported in the magnet body. When no current flows, the spring elementstherefore press against the armature disk such that it is pressed ontothe coating support, which supports brake coatings on the two axiallyoriented surfaces. The coating support is also connected to rotor shaft7 in a form-locked manner in the radial and circumferential directions.Therefore, when no current flows through the brake coil, armature disk 2presses coating support 5 onto the friction disk 11 positioned axiallybehind the coating support.

Housing 15 of the electric motor has a mechanical interface to bearingsupport 1, which means that bearing support 1 is connectible to housing15 in a sealed, rigid, and exact manner. Bearing support 1 has acorrespondingly matching interface.

Bearing support 1 has an additional, electric interface to the terminalbox constructed as a connection box. This includes a housing cover 14and a bottom part 4 of the terminal box, the bottom part beingconnectible to bearing support 1 in a sealed and rigid manner. A seal 16is provided in the connection region for this purpose.

The interface between housing 15 and bearing support 1 may also beconstructed to provide a sealed connection. Seal 17 is provided forthis.

Bottom part 4 of the terminal box has screw-type conduit fittings 18arranged as cable outlets. As an alternative, screw-type conduitfittings may be provided in the corresponding cover.

Seals 17, 16 may be arranged to function as a heat barrier.Consequently, the exchange of heat between the metallic parts, e.g.,housing 15 and bearing support 1, may be sharply reduced. The exchangeof heat between the bearing support and the bottom part of the terminalbox may be sharply reduced.

An additional measure for reducing this heat exchange is to not makebottom part 4 of the terminal box out of metal, but out of plastic oranother thermal insulator. Seal 16 may not only be arrangeable as a flatseal or O-ring, but also as a thermally insulating, injection-moldedpart, which separates the spatial region of bearing support 1, togetherwith the brake and the fan, from the interior of the bottom part of theterminal box, or also from cover 14.

On the B side, bearing support 1 has an opening for air to pass through.For reasons of safety, it is terminated by a fan-hood grating 19.

As illustrated in FIGS. 1 a and 1 b, a seal is also provided betweenbottom part 4 of the terminal box and corresponding cover 14. It may bearranged to be thermally conductive so that heat from the electroniccircuit may be discharged through the cover to not only the environment,but also the bottom part of the terminal box. In this context, heat isconducted via the contact surfaces of bottom part 4 of the terminal boxand corresponding cover 14, which extend around the spatial region ofthe seal itself, the seal being designable as a flat seal, O-ring, etc.Heat may then be discharged by the cover to the bearing support and tothe environment, since the bearing support has the function of forming ahousing. In contrast to this, the seal may not be thermally conductive,but rather may be arranged as a thermal barrier, whereby for this, thecontact surfaces are then designed to be small, and an additional heatbarrier may be inserted.

However, seal 16 may also be arranged to be thermally conductive, e.g.,metallic contact surfaces provided around the spatial region of the sealmay be increased in size, and therefore, a sufficiently large contactsurface may be provided which causes a reduction in the heat-transferresistance. This provides that bearing support 1 and the bottom part ofthe terminal box are effectively thermally coupled, i.e., they have alow heat-transfer resistance. Therefore, the heat may be discharged bythe electronic circuit, through the bottom part of the terminal box, tonot only the environment, but also the bearing support. Thus, aspecially formed cooling body is not necessary, and on the whole, asmaller volume is necessary, e.g., laterally.

Seal 17 may also be designed to conduct heat. This is advantageous, whenthe temperature in the stator and the corresponding housing isconstantly less than in the region of the bearing support and heat maytherefore be conveyed to the stator and its housing. Consequently, theentire electric motor may be designed to be even smaller.

Bearing support 1 may be provided with the two, above-mentioned,specific interfaces. Consequently, components other than thoseillustrated in FIGS. 1 a and 1 b are also alternatively connectible.

It may also be provided that the electronics are arranged not in theaxial direction, but rather radially, i.e., laterally. In this context,it may be provided that the overall length may be kept small. In thecase of most machines and systems, a certain volume is available on theside and accessible to the operator, since the connection box of themotor lies mostly on the side and the overall length is more expensivewith regard to the total cost. The laterally available volume isutilized, and the increase in volume needed in the lateral direction isinsignificant. In particular, cooling with the aid of a fan allows theelectronics to be manufactured to be small and therefore produces asmall lateral volume. In addition, the cooling body may be arranged tobe small, or may be neglected, since heat is discharged through thebearing support of the motor and discharged from it to the environment,via the stream of cooling air driven by the fan.

As illustrated in FIGS. 2 a and 2 b, instead of bottom part 4 of theterminal box, a differently formed bottom part 26 is put on andconnected in a sealed, detachable manner. It juts out in the directionof the motor. This provides space for signal electronics and powerelectronics in the interior of bottom part 26 and housing cover 25. Thepower supply cable and also signal lines and bus lines, e.g., field-buslines, are led through screw-type conduit fittings 20, which means thatthe entire electric motor may be arranged to have a high degree ofprotection, e.g., at least IP65, as does the electric motor illustratedin FIGS. 1 a and 1 b as well.

Connection terminals 22 are provided on a printed circuit board 23,which is provided in the interior of lower part 26.

A further feature is that the axial end of the cover and of bottom part26 is terminated in substantially the same axial position as the fanhood.

Provided in the interior is a printed circuit board 21 that isdetachably connected to the housing cover. It supports the signalelectronics.

A printed circuit board 23 having power electronics 27 is arranged inbottom part 26, the printed circuit board supporting a plug-and-socketconnector for an electrical plug connection to a further plug-and-socketconnector, the further plug-and-socket connector being connected toprinted circuit board 21. Power electronics 27 are connected to bearingsupport 1 in a thermally conductive manner. For this purpose, thebearing support has a precision-machined surface that may be used as acontact surface. Heat-conduction paste may also be added to improve theheat-transfer resistance.

Therefore, bearing support 1 is manufactured to be a multifunctionalpart. Thus, it not only has the above-mentioned mechanical interfaces,but is also used for discharging the heat of the power electronics tothe environment. To improve this dissipation of heat, it may be providedthat the fan additionally and actively supplies the bearing support withcooling air from the environment. Consequently, not only the stator ofthe electric motor, but also power electronics 27 may be cooled.

The signal electronics and power electronics are manufactured togetheras a converter. Consequently, the stator of the electric motor may bepowered by this converter, and the entire electric motor is thuscontrollable from the converter. The converter may be powered bythree-phase current.

The power electronics include at least the rectifier and the outputstage controllable in a pulse-width-modulated manner, i.e., theinverter, which generates, from the rectified voltage, an a.c. voltagehaving a frequency predefined by the control electronics. Thecorresponding electronic circuit breakers give off the heat generated bythem to a support, which is connected to bearing support 1 in athermally conductive manner. The support is mechanically connectible tothe bearing support, e.g., in a force-locked manner.

The power electronics may be connected to the cover in a thermallyconductive manner, the cover having a contact surface suitable for heattransfer.

The same stator with housing 15 is illustrated in FIGS. 3 a and 3 b, buta different bearing support 30 is connected. Bearing support 30 has thesame interface to the stator and to housing 15. However, the terminalbox is constructed in one piece with bearing support 30. This may reducethe manufacturing costs. A housing cover 31 is provided. Since no brakeis provided, and because of the one-piece arrangement and the omissionof fasteners associated with this, the electric motor as a whole may bemanufactured to be much more compact.

Fan-hood grating 32 may be manufactured to be substantially identical tofan-hood grating 19 illustrated in FIGS. 1 a, 1 b, 2 a, and 2 b.

Labyrinth seal 33 and shaft sealing ring 34 allow manufacturability witha high degree of protection, e.g., at least IP65. Labyrinth seal 33makes a seal between the bearing support and the rotating fan, theoccurring friction losses being very small. Shaft sealing ring 34 mayimprove the sealing function considerably. The one-piece formation ofthe bottom part of a terminal box may allow a high degree ofimperviousness and protection to be achieved in a cost-effective manner,using simple arrangements.

Another variant is illustrated in FIGS. 4 a and 4 b. In this context,bearing support 30 of FIGS. 3 a and 3 b is reused. The stator andhousing 15 are also the same. However, a sensor is provided, which ismechanically and detachably connected to the bearing support andelectrically connected to an electronic circuit that may be provided inthe interior region or exterior region of the terminal box. In the caselast mentioned, the signal lines of the sensor are led out throughscrew-type conduit fittings 35 of the terminal box. The sensor detectsmagnetic foil 41, which is applied to the fan and is provided with analternating direction of magnetization at the circumference. As analternative, a plastic-bonded ferrite having an alternating direction ofmagnetization may be provided.

A series of electric motors is provided, which allows different variantsto be produced as a function of the application of the motor, where,however, as many parts as possible are reusable within this modularsystem. For example, the same stator, together with housing 15, isconnectible to different bearing supports, a first bearing supportincluding a brake and a fan, and a second bearing support only includinga fan. In addition, the first bearing support is connectible, with theaid of its upwardly directed interface, to a terminal box, i.e.,connection box, or to a converter or to a different electronic device.

Illustrated in FIGS. 5 a and 5 b are a plan view and sectional view of abearing support, a terminal box being cast integrally. In this context,the bearing support has depressions 51 for a labyrinth seal. Knockout 52is present after the manufacture of the bearing support and is easilyremovable in a simple manner, when an opening is necessary foraccommodating the sensor. Mere pressing with a tool is sufficient. Thecooling air heated by the bearing support flows through cut-outs 53.

An alternative bearing support 63 is illustrated in FIGS. 6 a and 6 b,terminal box 64 being formed separately. A seal 61 is inserted toproduce a sealed connection to bearing support 63. In addition, theterminal box is formed at the interface to the bearing support such thata keyed connection is provided, which simultaneously protects the seal,i.e., the function of forming the housing for it is also implemented.

Provided for mounting a sensor are knockouts 62, which may bemanufactured inexpensively and are easily removable during the mounting.

Spatial, oblique views from the front and back, which belong to bearingsupport 63 illustrated in FIGS. 6 a and 6 b, are illustrated in FIGS. 10a and 10 b. Mounted and detachably connected terminal box 64 isillustrated as well. Cut-outs 53 for letting air through areillustrated. The fan grating, where the air is sucked in, is notillustrated. The air then flows out at the other axial end of bearingsupport 63 such that the air stream is directed through housing 15 ofthe electric motor and also has a cooling effect there for dissipatingheat.

Spatial, oblique views from the front and back, which belong to bearingsupport 30 illustrated in FIGS. 5 a and 5 b, are illustrated in FIGS. 11a and 11 b. Cut-outs 53 for letting air through are illustrated. The fangrating, where the air is sucked in, is not illustrated. The air thenflows out at the other axial end of bearing support 63 such that the airstream is directed through housing 15 of the electric motor and also hasa cooling effect there for dissipating heat.

As illustrated in FIGS. 7 a and 7 b, the electric motor is provided witha fan, but without a brake. The terminal box is screwed onto bearingsupport 63 and, with the aid of seal 61, it is connected to form a seal.Cover 31 is put onto terminal box 64 and connected to it so as to form aseal, terminal box 64 including screw-type conduit fittings 35.

An electric motor, which is manufactured to be similar to the oneillustrated in FIGS. 7 a and 7 b, is illustrated in FIGS. 8 a and 8 b.However, knockouts 62 are removed and sensor 40 is inserted. The sensoris mounted so as to be vertically adjustable. This is implemented, forexample, with the aid of two lock nuts. However, other methods may beused for vertical adjustment as well. Sensor 40 is therefore adjustableto the optimum distance from the fan and may thus generate pulses perrevolution in accordance with the sensor vanes or fan blades.

An electric motor, which is manufactured to be similar to the oneillustrated in FIGS. 7 a and 7 b, is illustrated in FIGS. 9 a and 9 b.However, instead of the terminal box, a bottom part 91 is mounted onbearing support 63. A housing cover 14 is put onto bottom part 91. Anelectronic circuit, as is also mentioned in the description of FIGS. 2 aand 2 b, may be provided in the interior chamber surrounded by bottompart 91 and housing cover 14. Thus, a converter, a soft-start circuit, amotor switch, or another electronic circuit may be implemented.

The sensor may be directly mounted to printed circuit board 23, and theprinted circuit board may be able to be positioned very accurately.Therefore, this arrangement directly allows the sensor to detect thealternating direction of magnetization at the fan. Information regardingthe rotational speed and direction of rotation may be derived from thesensor signals. This allows the electric motor to be controlled and/orregulated in an improved manner.

The signal electronics and power electronics may not take the form of aconverter, but rather a soft-start device, i.e., starter. This allowscosts to be reduced.

As an alternative, the signal electronics and power electronics may bearranged as a switch for switching the motor on and off, the switchbeing able to be implemented electromechanically or electronically.

Other motor electronics may also be provided as signal electronics andpower electronics. For example, the motor electronics may be arranged asa voltage-adjustment module for the motor and/or the brake, or as abroad-voltage module for the motor and/or the brake.

At least a part of the power electronics may be connected to the coverin a thermally conductive manner. To this end, the inner side of thecover may be machined such that the heat from the power electronics maybe transferred to it. This connection may be implemented in aforce-locked manner. However, other types of connections may also beprovided.

The signal electronics may also include powerline electronics. Thismeans that the electronic circuit is able to modulate information ontothe supply lines, e.g., power cables, using, in particular, a frequencymuch higher than, e.g., 50 Hz. For example, frequencies between 10 kHzand 10 MHz may be suitable.

The bearing support may be formed of diecast aluminum. However, it maybe provided to make the bearing support out of thermally conductiveceramic. Therefore, a low-wear friction surface may be provided for thebrake, the heat of the friction surface generated during braking beingable to be removed quickly and easily from the bearing support.

It is also possible to make only the friction surface out of ceramic.

The bearing support may also be made of cast iron, e.g., gray cast iron.

1. An electric motor, comprising: a stator; a rotor including a rotorshaft; a bearing support including a bearing seat for a B side bearingof the rotor shaft; and a housing including at least one firstmechanical interface adapted to connect to the bearing support; whereinthe bearing support includes a further interface adapted to connectdirectly to a bottom part, the bearing support forming a cup-shapedhousing for a brake and a fan and extending beyond the brake and the fanin an axial direction away from the B-side bearing, the cup-shapedhousing terminated on one end by the B-side bearing and the rotor shaftand terminated on an opposite end by an approximately planar grating,the terminated cup-shaped housing enclosing the brake and the fan, thebottom part having an interface adapted to connect to a cover, thebottom part forming a housing for at least power electronics, heat fromthe power electronics dischargeable one of (a) directly and (b) at leastindirectly to the bottom part, the bottom part thermally conductivelyconnected to the bearing support to discharge the heat of the powerelectronics by the bearing support to surrounding air.
 2. The electricmotor according to claim 1, further comprising a seal arranged betweenthe bearing support and the housing assigned to the stator.
 3. Theelectric motor according to claim 1, wherein the power electronics arethermally conductively connected to the cover at a contact surface. 4.The electric motor according to claim 1, wherein the cover is thermallyconductively connected to the bearing support by the bottom part todischarge heat from the power electronics to the surrounding air.
 5. Theelectric motor according to claim 1, wherein an air stream of the fan isadapted to cool the bearing support.
 6. The electric motor according toclaim 1, wherein the bearing support is adapted to discharge heat to anenvironment.
 7. The electric motor according to claim 1, wherein thebearing support includes cut-outs, a stream of cooling air directablethrough the cut-outs.
 8. The electric motor according to claim 1,wherein the bearing support is shaped to be suitable to direct air of anair stream of the fan.
 9. The electric motor according to claim 1,wherein the bearing support includes at least one of (a) connectionterminals and (b) centering devices for at least one of (a) additionalunits and (b) additional devices positionable on the B side.
 10. Theelectric motor according to claim 9, wherein at least one of (a) theadditional units and (b) the additional devices include at least onerotating component one of (a) directly and (b) indirectly connectible tothe rotor shaft of the electric motor and at least one non-rotatingcomponent at least one of (a) connectible to the bearing support and (b)centerable on the bearing support.
 11. The electric motor according toclaim 9, wherein at least one of (a) the additional units and (b) theadditional devices include angular-position sensors.
 12. The electricmotor according to claim 1, wherein the bottom part and the cover areadapted to form a housing for a sensor adapted to detect at least onephysical characteristic of at least one of (a) a rotationally mountedpart of the electric motor and (b) a fan blade.